Both TQ2-12V and TQ2-12V-3 are unavailable. Any alternative ?
opa210 is back in stock at mouser, but the 2210 is mid-february
opa210 is back in stock at mouser, but the 2210 is mid-february
Most tend to have backorders from memory at the moment. I want some additional components for other projects but they have stock for now.
Only thing i don't have on the bom is the connectors.
If someone could double check - you will need to sort out some connectors for these. In the archive are two BOMs - one for the DAC and one for the filter.
You can go to BOMs in the mouser window, then import the BOM xls (set the header row, and the mouser/manufacturer/quantity columns then import). You will then have you own BOM for that component you can save. I have the original opamps - so they are currently out of stock.
You can go to BOMs in the mouser window, then import the BOM xls (set the header row, and the mouser/manufacturer/quantity columns then import). You will then have you own BOM for that component you can save. I have the original opamps - so they are currently out of stock.
Last edited:
Finding an alternative for the TQ2-12V relays is more difficult than I had hoped. There are plenty relays with about the right electrical characteristics that are in stock at Mouser, but they all have a different size or different pinning.
The one that looks most usable is the Omron G6K-2P-DC12 (euro 4.44, 1573 in stock). It has 5.08 mm instead of 7.62 mm of distance between its rows of pins, but hopefully the pins can be very carefully bend out a bit to make it fit on the PCB. It has only eight rather than ten pins, but the pins that are missing are not connected pins (5 and 6 on the TQ2).
Another option might be to try it without the relays. I have no idea how loud or how soft the resulting turn-on and turn-off thumps will be. Format switching thumps will still be blocked via the set inputs of U22, U24, U26 and U27.
The one that looks most usable is the Omron G6K-2P-DC12 (euro 4.44, 1573 in stock). It has 5.08 mm instead of 7.62 mm of distance between its rows of pins, but hopefully the pins can be very carefully bend out a bit to make it fit on the PCB. It has only eight rather than ten pins, but the pins that are missing are not connected pins (5 and 6 on the TQ2).
Another option might be to try it without the relays. I have no idea how loud or how soft the resulting turn-on and turn-off thumps will be. Format switching thumps will still be blocked via the set inputs of U22, U24, U26 and U27.
Last edited:
Thanks for the Mouser BOMs Nick, I've just ordered the parts to, hopefully, assemble a DAC board over Christmas - it'll be complete except for the OPA2210s 😞.
I'll also retry the 'CD Enhancer' output stage over the Christmas break, this time with some caps between it and the DAC board output header.
Marcel, just wondering if a variation of the Valve DAC output filters might be a possibility given your grounding arrangement?
Marcel, just wondering if a variation of the Valve DAC output filters might be a possibility given your grounding arrangement?
Some TQ2-12V will be available the 08/02 at Farnell.
I am currently trying to make board with the few things i need. Not easy considering it's the first pcb i ever made. 🙂
Also for all my build i am using Takachi case, mostly UC serie. They have a beautiful Bronze anodized color with silver front. I build my headphone amp with this case and it's gorgeous. However they change their offer, now the standard UC serie have standard color. They made a new series with custom ordered size. I don't know if there is a MOQ or if the reseller i'm used to can order them...
Anyway we can have a beautifull case that fit perfectly the dac, if someone is interested.
You could use LC filters if you can live with a relatively low signal level. With LC filters that are only terminated at their inputs, you would get about 442 mV RMS per side, so 884 mV RMS differential, when the input signal is a sine wave that modulates the DSD stream between 25 % and 75 % ones (0 dBFS level for DSD). The common-mode voltage would be about 1.25 V.
An output transformer could make the output suitable for connection to an unbalanced input, and maybe transform the voltage up a bit. The trick would then be to keep its impedance from disturbing the filter alignment.
If you reduce C15, C26, C42 and C53 on the DAC main board to 4.7 nF and then add 1.8 mH inductors and 15 nF capacitors, you have approximately third-order Butterworth filters at 45 kHz. You may need to add coupling capacitors if you want to get rid of the 1.25 V DC level.
Thanks Marcel. I was expecting a lower output but I can tolerate that in my system context as I'm attenuating the signal into my amps quite a bit and if required there are some options for balanced to single-ended conversion with gain, like the Broskie Unbalancer;
https://www.tubecad.com/2013/09/blog0270.htm
https://www.tubecad.com/2013/09/blog0270.htm
Thanks! Zettler AZ850-12 is the perfect replacement for the TQ2-12V and Conrad has 545 of them in stock.
Just a reminder that a few Group Buy subscribers still need to settle with me for the postage costs, see the amber cells in the spreadsheet;
https://docs.google.com/spreadsheets/d/1uKnO0GdXeRVG1_gdMzKvs1F0184cyWlzM4Ul6nbt7Io/edit#gid=0
Thanks to everyone who has already settled.
Have any UK members received their PCBs yet?
https://docs.google.com/spreadsheets/d/1uKnO0GdXeRVG1_gdMzKvs1F0184cyWlzM4Ul6nbt7Io/edit#gid=0
Thanks to everyone who has already settled.
Have any UK members received their PCBs yet?
Not yet, although being COVID positive at the moment I've not ventured out.. given the postal issue it may be a week..